The median/average age of the population of Mount Nelson is 40 years of age.

76.0% of people living in the suburb of Mount Nelson were born in Australia. The other top responses for country of birth were 5.2% England, 1.8% China , 1.4% New Zealand, 0.9% South Africa, 0.9% Scotland, 0.8% Netherlands, 0.8% United States of America, 0.6% Ireland, 0.5% Germany, 0.5% Malaysia, 0.4% Canada, 0.4% Korea, Republic of , 0.4% Thailand, 0.4% Hong Kong .

87.8% of people living in Mount Nelson speak English only. The other top languages spoken are 3.3% Language spoken at home not stated, 2.1% Mandarin, 1.0% Other, 0.7% French, 0.6% German, 0.5% Japanese, 0.4% Thai, 0.4% Greek, 0.4% Dutch.

46.9% of people are married, 36.1% have never married and 10.6% are divorced and 2.2% are separated. There are 85 widowed people living in Mount Nelson.

53.4% of the people living in Mount Nelson over the age of 15 and who identify as being in the labour force are employed full time, 36.0% are working on a part time basis. Mount Nelson has an unemployment rate of 5.3%.